Experimental studies on primary and secondary pyroelectric effects in Pb(ZrxTi1 - x)O3, PbTiO3, and ZnO thin films

The pyroelectric coefficients and pyroelectric response in lead zirconate titanate (Pb(Zr_xTi_1-x)O₃), lead titanate (PbTiO₃), and zinc oxide (ZnO) thin films (0.1-2.0-μm thick) have been studied for possible integrated thermosensor applications. Pyroelectric properties of these films deposited on thick (500-μm) silicon substrates and thin (1.0-μm) polysilicon membranes have been investigated. The measured pyroelectric coefficients for these materials are 70, 95, and 1.0 nC/cm² K for Pb(Zr_0.54Ti_0.46)O₃, PbTiO₃, and ZnO, respectively. Coupling effects between the pyroelectric film and substrate were studied. It was observed that the primary pyroelectric effect dominates the pyroelectric response in Pb(Zr_0.54Ti_0.46)O₃ and PbTiO₃ thin films while the secondary effect is dominant in ZnO thin films.